I wake to the sound of distant explosions. The dull boom rattles my bedroom window, gentle tremors traveling through the floorboards to my bed frame. It's not an attack or a villain—just my sister, Karui, training out back as usual. Dawn light filters through the curtains, pale and gray, and for a long moment I simply lie there listening.
Each thud in the distance is rhythmic; she must be running drills again, blasting targets methodically. Boom. Boom. Boom.
The pattern is steady, almost comforting in its familiarity, yet underlaid with a tension that sits heavy in my chest. Karui never misses a morning, not even on important days like today. Especially not on days like today.
Today is the U.A. High entrance exam. It's one of the most competitive exams in the country—the gateway into the top hero academy. For her, it's everything. I know she's prepared; she's been preparing for years, driven by something I can't quite grasp. Still, I worry.
I rub the sleep from my eyes and force myself out of bed. My legs feel heavy this morning, more from dread than fatigue. In the bathroom, I splash water from the tap over my face, clearing the last webs of sleep from my mind. I turn off the faucet and lift my gaze to the mirror.
There he is—same as always—me: Kaito Yanagi, age fourteen, average height, with messy dark hair sticking out at odd angles, and tired hazel eyes. And there, slanting across my right cheekbone and over the bridge of my nose, is the pale scar that divides my reflection in two.
I trace the scar with a damp fingertip. It's faintly shiny in the fluorescent light, a thin line of slightly raised skin that never quite tanned like the rest of me. It doesn't hurt. But seeing it still sends a dull ache through my chest. It's a reminder of that day, of how everything changed for us. I was nine when it happened; Karui was ten. It was the day her quirk first showed its ugly, destructive side—and the day I learned how fragile I really was.
My eyes unfocus, the present blurring into memory. In my mind, I'm back at the small park a few blocks from where we used to live, on a sweltering summer afternoon, cicadas screaming in the trees. I can almost smell the cut grass and feel the humidity clinging to my skin. We were just kids.
I remember Karui's laughter as she chased me, the two of us playing hero and villain (back then I always pretended to be the villain, because she insisted on being the hero). I was "escaping" with a goofy grin, and she was hot on my heels. Neither of us had any idea what was about to happen.
We had drawn an audience of local kids—some older boys from down the street. They leaned on the fence, jeering. I noticed them only when the laughter changed pitch.
"Hey," one of them said, squinting at us. "Isn't that her?"
Another leaned closer, eyes lighting with recognition. "Yeah. That's Yanagi's kid. I heard she recently got her quirk."
Their voices dropped, quick whispers passing between them as they looked back and forth from Karui to me.
"So who's the other one?"
A pause. Then a snort.
"That's her brother. Pretty sure he doesn't even have a quirk. He's quirkless."
Laughter followed. I heard them as I kept running, cape flapping behind me as I played the villain. The irony wasn't lost on them. A quirkless kid pretending to be the bad guy in a world where strength decided everything.
Quirkless. At age nine, I already burned with shame. By then it was obvious I was one of the unlucky 20% born without any power in a superhuman society. I'd known since I was six, when the doctor pointed at the X-ray of my foot showing an extra joint in my pinky toe – a telltale genetic marker of having no quirk. No quirk, no powers, nothing to admire. Just a regular kid. Those older boys made sure I knew that.
I tried to ignore them and keep playing, but I wasn't as good at tuning out the taunts as I pretended. Karui heard them too; I saw her glance their way, saw her smile falter. "Don't listen," I mumbled to her, cheeks burning. I remember forcing a grin. "C'mon, hero, catch the villain!" I took off again, hoping she'd just laugh and chase me.
But she didn't. Not right away. The bullies' comments had hit a nerve. Karui's pride was prickly even then—especially when it came to me. Weak, worthless. Those were the kinds of things people said about quirkless kids, the kinds of things I'd started to believe about myself. Karui couldn't stand it.
I should have noticed the warning signs: her fists clenching, the way she bit her lip. I should have calmed her down somehow. Instead, I went on running, thinking she was right behind me.
"Take it back!" I heard her shout. I spun around just in time to see one of the boys flinch. Karui had stepped up to the fence, anger radiating off her small frame. She was defending me, as she always did, fearless against boys twice our size. "My brother's not worthless!" she yelled. I opened my mouth to call her away—maybe we could just run, play somewhere else—but I never got the chance.
It happened in an instant. One of them—the tallest boy—reached out, maybe to shove her or maybe just to flick her forehead mockingly. He barely made contact. But that slight provocation was enough. Later, she told me it felt like something inside her burst. One moment her hands were empty; the next, WHOOOM—a blinding flash and a concussive blast of heat. The fence exploded apart with a thunderclap. I saw splinters, dirt, and a wave of force rippling outward.
The world tilted.
I don't remember hitting the ground, but I must have. When my vision cleared, I was on my back staring at the sky, ears ringing. The acrid stench of burning grass stung my nose. I sat up in a daze, heart pounding in my throat. The wooden fence was obliterated—charred fragments littered the yard. The bullies had scattered, screaming in terror as they fled down the street. And Karui… Karui was standing at the epicenter of the blast, her arms still raised defensively, palms out. She was shaking. Wisps of smoke curled from her fingertips. Her eyes were wide in shock at what she'd done.
Then she saw me on the ground and rushed over. "Kaito!" I can still hear the panic in her voice. My head was ringing so badly I couldn't answer at first. There was a wet warmth on my cheek. When I touched my face, my fingers came away red. A shard from the fence had slashed across my cheekbone—blood dripped onto my shirt. I remember my hands starting to tremble, more from fear than pain.
Karui's face went as white as chalk. "I'm sorry—I'm so sorry!" she cried. She tried to press her small hands over the cut to stop the bleeding, but they were trembling too hard and she didn't know what to do. Tears welled up in her eyes, matching the ones blurring my own vision. I realized she was terrified—of herself, of hurting me. In that moment, despite my own pain, my heart clenched for my sister. She'd always been strong for me. Now she looked so vulnerable, horrified by her own power.
I did the only thing I could think of: I grabbed her hand. "It's okay, Rui," I managed to choke out. My cheek was burning and sticky, and I tasted copper, but I mustered a smile for her. I used her nickname, the one only our family uses. "I'm okay. It wasn't your fault." The words came out in a soothing babble. I don't know if I was trying to calm her or myself. Probably both.
Her quirk had shown itself—a fierce, explosive power—and I was the one caught in it. But even lying there dazed and bleeding, I didn't blame her. Not then, not ever. It wasn't her fault that I was quirkless and slow. If anything, I blamed myself for being too weak to withstand it.
Everything after that is fragments: our mother screaming when she ran towards us and saw us, the frantic rush to the clinic, stitches for the cut on my face. Karui sobbing uncontrollably and apologizing to me a thousand times. And our father… Father's reaction stands out clearest of all.
I recall sitting on the edge of a hospital bed, the sting of antiseptic in my wound, as Father stalked in. Isamu Yanagi cut an imposing figure in his black coat, jaw set in grim lines. A former covert hero operative, Father was not the warmest man even on a good day. But that day he was livid. Not at me—for once, he barely spared me a glance beyond a curt, "How bad is it?" (the doctor said it would scar, and Father just grunted). No, his fury was focused on Karui.
She stood rigid by the doorway, eyes puffy from crying, and started to stammer another apology when he rounded on her. "Quiet." His voice was low, cold. I fell silent, and Karui did too, like a switch had been flipped.
Father's eyes were blazing, with a fierce intensity. "This is what happens when you lose control," he said, enunciating each word slowly. Karui's lip trembled. I expected him to yell that she could have killed me or those boys. But he didn't.
Instead he knelt down until he was at eye level with her. "Power without control is useless. You will train this quirk, Karui. I will see to it myself." His gloved hand rested on her shoulder—not gently, but not harshly either. "Do you understand?"
Karui gulped and nodded, fresh tears spilling. Father pulled back, nodding in return. "Good." In that moment, I felt invisible. My cheek throbbed, but Father didn't ask if I was okay. His attention was already back on Karui's potential.
He saw in her quirk what he valued most: power, strength. And strength was everything to him. He'd once told us that being strong wasn't just important, it was our moral duty—that to be weak was to fail those who mattered. I was too young then to fully grasp it, but sitting there in that hospital room, I felt the sting of those words. Weakness was an ethical failing in my father's eyes. And me? I was the quirkless kid with a bleeding face—a living embodiment of weakness.
That was the day Father's focus on Karui truly began. As soon as I was patched up, he threw himself into training her—early mornings, late nights, drilling her in technique and tactics as if she were a soldier. He started when she was ten, and he never really stopped.
Over time, under his tutelage, Karui's control over her "explosion-adjacent" quirk grew exponentially. Father was proud. "She has my technique, my tactical mind," I once overheard him boast to an old colleague. "She'll be unstoppable."
Meanwhile, I… Well, I was there for those years, too, somewhere in the background. The quirkless son, good for fetching water and towels, quietly cheering from the sidelines. Father didn't say it, but I knew I "took after nobody."